/****************************************************************************
 * Copyright 2009 Huascar A. Sanchez                                        *
 *                                                                          *
 * Licensed under the Apache License, Version 2.0 (the "License");          *
 * you may not use this file except in compliance with the License.         *
 * You may obtain a copy of the License at                                  *
 *                                                                          *
 *     http://www.apache.org/licenses/LICENSE-2.0                           *
 *                                                                          *
 * Unless required by applicable law or agreed to in writing, software      *
 * distributed under the License is distributed on an "AS IS" BASIS,        *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
 * See the License for the specific language governing permissions and      *
 * limitations under the License.                                           *
 ****************************************************************************/
package com.gotobject.filter.internal;

import com.gotobject.filter.FilterImpl;
import com.gotobject.filter.predicate.Predicate;
import com.gotobject.filter.spi.ContextFluency;

import static java.util.Arrays.asList;

/**
 * @author huascar.sanchez@gmail.com (Huascar A. Sanchez)
 */
public class Contracts {
    private static final int NIL = 0;

    private Contracts(){}

    public static <T> void checkIfWhereKey(FilterImpl filter, Predicate<? super T>... predicates) {
        final ContextFluency check = filter.getApiFluencyCheck();
        if(asList(predicates).contains(null) || predicates.length == NIL) {
            filter.addError("null predicate are not acceptable.");
        } else {
            for(Predicate<? super T> each : predicates){
                if(!check.isWhere(each)) {
                    filter.addError(each + " is not a predicate that can be used with the where statement.");
                }
            }
        }
    }

    public static <T> void checkIfSelectKey(Predicate<? super T> key, FilterImpl filter) {
        final ContextFluency check = filter.getApiFluencyCheck();
        if(!check.isSelect(key)) {
           filter.addError(key + " is not a predicate that can be used with the select statement.");
        }
    }
}
